采用FLAC3D数值分析软件,开展龙首矿岩体流变特性研究,结果表明,巷道围压的增大加大了岩石蠕变速率,加快岩石损伤、变形和破坏过程;揭示围压对围岩流变特性影响规律,巷道围岩变形主要表现为岩石峰后剪胀变形,且低围压条件下对围压敏感性较强,受围压控制效果更明显,当围压小于4 MPa时,其影响程度为岩石体积应变的70%-80%。现场监测表明,锚杆托锚力为锚固能力的9.15%-33.79%,支护阻力不足以抑制龙首矿流变围岩变形的继续发展,岩石变形速率为0.043-0.149 mm/d,且有减缓趋势,但变形量持续增加,且水平方向变形大于垂直方向变形,不利于巷道工程围岩的稳定,应采取适当的支护加固措施。
The rock mass rheological characteristics of Longshou mine were studied by FLAC3 D numerical analysis software. The results show that the rock creep rate increases and rock damage,deformation and failure process accelerates with the increase of confining pressure. The impacting law of confining pressure on rock rheological properties is revealed. The deformation of surrounding rock mainly presents as dilatancy deformation after peak strength,and the sensitivity of confining pressure is more obvious when the confining pressure is lower. While the confining pressure is less than 4 MPa,the affecting degree reaches to 70%–80% of rock volumetric strain. The on-site monitoring of bolt stress and roadway deformation is conducted to explore the rock mass rheological rule and supporting effect. The results indicate that the anchoring force is just 9.15%–33.79% of the anchoring capacity,insufficient to suppress the rock deformation. The deformation rate is 0.043–0.149 mm/d and has a slowing down trend,but the amount of deformation increases gradually,with a greater horizontal convergence than the vertical of that,which is not conducive to the stability of surrounding rock,so the appropriate reinforcement measurements should be adopted.